Multipositional switch construction

ABSTRACT

There is disclosed a multipositional switch comprising a rotatably mounted switching wheel equipped with a rotary wiper switch means possessing at least two contact fingers. A circuit board having a plurality of contact tracks, for instance in the form of a number of contact segments and one ring-shaped contact member, cooperate with the rotary wiper switch means such that for each selected position of the switching wheel at least two of the contact tracks are electrically coupled with one another via the contact fingers. The circuit board possesses a plurality of spaced recesses, and cam means are provided for at least one of the contact fingers. The cam means for each switching position of the switching wheel being located in an associated one of said recesses. Upon rotation of said switching wheel into its next switching position, the cam means move out of the associated one recess and along the surface of the circuit board, to thereby rapidly raise the contact finger provided with such cam means from its associated contact track located at the circuit board.

United States Patent [72] Inventor Helmuth Spreitur Zurich, Switzerland[21] Appl. No. 816,257 [22] Filed Apr. 15,1969 [45] Patented May 18,1971 [7 3] Assignee Contraves AG Zurich, Switzerland [32] Priority May13, 1968 [33] Switzerland [31] 7085/68 [54] MULTIPOSITIONAL SWITCHCONSTRUCTION 7 Claims, 4 Drawing Figs.

[52] US. Cl..-. 200/11, 200/17, 200/166 [51] Int. Cl. H0lh 19/58, HOlh21/78, l-lOlh 3/00 [50] Field otSearch 200/5, 11, 17, 166(C), 166(CPC),166.1

[56] References Cited UNITED STATES PATENTS 2,755,347 7/1956 Allison200/1 1(D) 3,030,461 4/ 1962 Gantz 200/166(. 1 )X Primary Examiner-J R.Scott Attorney-Wemer W. Kleeman ABSTRACT: There is disclosed amultipositional switch comprising a rotatably mounted switching wheelequipped with a rotary wiper switch means possessing at least twocontact fingers. A circuit board having a plurality of contact tracks,for instance in the fonn of a number of contact segments and onering-shaped contact member, cooperate with the rotary wiper switch meanssuch that for each selected position of the switching wheel at least twoof the contact tracks are electrically coupled with one another via thecontact fingers. The circuit board possesses a plurality of spacedrecesses, and cam means are provided for at least one of the contactfingers. The cam means for each switching position of the switchingwheel being located in an associated one of said recesses. Upon rotationof said switching wheel into its next switching position, the cam meansmove out of the associated one recess and along the surface of thecircuit board, to thereby rapidly raise the contact finger provided withsuch cam means from its associated contact track located at the circuitboard.

. Patented -May181971 f 3,579,251

322 313 FIGJ.

, INVENTOR HELMUTH SPREITZER I ATTO YS BACKGROUND OF THE INVENTION Thepresent invention relates to an improved multipositional selector switchof the type incorporating a rotatable switching wheel at which there ismounted a rotary wiper switch means having at least two contact fingersin such a fashion that during each selectable switching position of theswitching wheel at least two contact tracks of a circuit board areelectrically coupled with one another.

In prior art multipositional selector switches of this generalconstruction, during the switching operation, the contact fingers of therotary wiper switch means slide from one contact track located upon thecircuit board onto the nonconductive portion of the circuit boardsituated between two contact tracks, and then onto the next contacttrack. Such type physical construction is, however, unsuitable for manyapplications or is at the very least subject to disturbances. Whenswitching current intensities above 0.3 amperes, the sparks which appearduring the switching operation cause a rapid charring of the material ofthe circuit board at the region of the contact track. Since the contactpoints or rivets wipe across the circuit board any contarninations whichare present upon the contact tracks will be entrained, which,- in turn,impairs the operational reliability of the switch.

SUMMARY OF THE INVENTION Accordingly, a need exists in the prior art toprovide an improved multipositional selector switch which effectivelyovercomes the aforementioned drawbacks-Thus, one primary objective ofthis invention is to provide a multipositional selector switch whichdoes just that.

Another, more specific object of the present invention is to provide animproved multipositional selector switch of the type mentioned which isrelatively simple in construction, extremely reliable in its switchingoperation, not readily subject to breakdown, avoids the heretoforementioned drawbacks of the prior art constructions, and improves thelongevity of the switching unit.

Still another more specific object of the present invention relates toan improved multipositional selector switch which is equipped with meansenabling the switching operation to'be performed while substantiallyreducing the fonnation of sparks which otherwise would tend to char thematerial of the circuit board and which allows the contact fingers to bemoved from one contact track to another without any appreciable dangerof spreading contamina'tions or foreign materials from one such contacttrack to another.

Yet a further significant object of the present invention relates to animproved multipositional selector switch which can be readily massproduced in economical fashion, provides for (a) increased longevity ofthe components of the switch, (b) operational reliability of the switchitself, and (c) suppresses to a great extent wearing out of thecomponents of the switch due to sparking, and (d) reduces malfunction ofthe switch by considerably avoiding spreading of foreign material alongthe circuit board and into contact with parts of the switch structure.

Now, in order to implement these and still further objects of theinvention, which will become more readily apparent as the descriptionproceeds, the proposed inventive multipositional selector switchconstruction is manifested by the features that a cam means is providedfor at least one contact finger. This cam means is located for eachswitching position of the switching wheel in a recess of the circuitboard provided for such cam means. Since the cam means, upon furtherrotation of the switching wheel into its next switching position, movesout of the recess onto the plane or surface of the circuit board andslides along such surface, there is brought about a rapid raising of thecontact finger from the associated contact track located upon or atthecircuit board.

By virtue of the inventive construction of multipositional selectorswitch, it is insured that the contact finger with its contact point orrivet is reliably and rapidly raised from a contact track and againplaced onto a contact track. In this manner it is possible to switchconsiderably larger currents without the presence of disturbing ordetrimental auxiliary affects, such as those experienced with the priorart constructions explained above. Likewise, soiling of the switchingcontacts is prevented due to the raising of the contact points or rivetsfrom the contact tracks, which, in turn, favorably influences theoperational reliability of the switch structure.

BRIEF DESCRIPTION OF THE DRAWING The invention will be betterunderstood, and objects other than those set forth above, will becomeapparent, when consideration is given to the following detaileddescription thereof. Such description makes reference to the annexeddrawing wherein:

FIG. I is a schematic side view of a multipositional selector switchconstruction according to the present invention;

FIG. 2 is a fragmentary view showing details of the rotary wiper switchmeans with its contact fingers and a portion of the circuit boardprovided with the contact track means and recesses;

FIG. 3 is a sectional view of the structure shown in FIG. 2, takensubstantially along the line' III-III thereof; and 7 FIG. '4 is aview ofthe entire circuit board illustrating details of the contact track meansand the recesses.

- DESCRIPTION OF THE PREFERRED EMBODIMENTS Describing now the drawings,the exemplary embodiment of multipositional selector switch constructiondisclosed herein will be seen to comprise a switch housing I for therotatably mounted switching wheel 2 and the circuit board or plate 3equipped with the contact track means 31 and 32. As will be explainedmore fully hereinafter, the contact track means 31 are in the form ofcontact segments whereas the contact track means 32 are here shown inthe form of a substantially ringshaped contact member. It will also beobserved that the switching wheel 2 is equipped with a plurality ofperipherally disposed teeth or finger-engaging projections 21, whereinfor each switching position of the switching wheel 2 a different one ofthese protruding teeth 21 extends out of the opening 10 provided at thefront side of the switch housing 1. A suitable spring member II withinthe switch housing 1 serves to retain the switching wheel 2 in itsmomentary located switching position. Furthermore, the through passageopenings or bores 12, which may be advantageously conical at the inside,for the purposes to be explained shortly, and serve to receive thefastening means for holding together a plurality of such multipositionalselector switch units into a composite switch assembly, will beunderstood to have these through passage openings 12 extended at oneside by outwardly conical sleeve members 13. These through passageopenings 12, together with the conical sleeve members 13, and theprotruding shaft 22 for the switching wheel 2 serve as alignment andretaining means for the correct mounting of the insertable or mountablecircuit board 3. Additionally, it is here mentioned that the protrudingsleeve members 13 at one side of the switch housing 1 will be receivedin the through passage openings 12 provided at an adjacent switchhousing 1, so that a plurality of such switch units can be convenientlymounted together in side-by-side relationship.

In FIG. 2 there are shown details of the rotary wiper switch means 4 andthe circuit board 3. It will be seen that the rotary wiper switch means4 is fixedly connected for rotation at the locations 42 with theswitching wheel 2. In the exemplary illustrated embodiment of switchconstruction depicted herein, both of the resilient contact fingers 41and 43, which advantageously each carry a respective silver contact pinor rivet 41' and 43', electrically couple in each switching position ofthe switching wheel 2 the substantially ring-shaped contact track 32with one of the contact tracks 31. Furthermore, it will 3 be understoodthat according to an important aspect of. the invention a cam member 44is provided for the contact finger 43. This carn member 44 is disposedsubstantially perpendicu-- lar to the associated circuit board 3.Whenever the switching wheel has assumed a predetermined switchingposition, the cam member 44 is located in a given recess 30 of thecircuit board 3. Again, it will be seen that in the exemplary embodimenta plurality of such recesses are disposed inv spaced arrangement aroundthe ring-shaped contact member 32, and specifically, between the latterand the associated contact segment 3!. Furthermore, the spacing betweenthe contact tracks 31,. 32 of the circuit board 3 at all locationsamounts advantageously to at least 3 mm.

FIG. 3 serves to explain the mode of operation of the depictedmultipositional selector switchunit during the selection of a newswitching position. When the switching wheel 2 is indexed orrotated-further, and therefore also the contact finger 43 carrying thecam member 44, this cam member 44 will be raised out of its recess 30into the phantom line position where it slides upon the surface orplaneof the circuit board 3. Consequently, the associated contact pin orrivet 43' is raised from the contact track 31. If the switching wheel 2is rotated further, then, the cam member 44 will slide into theneighboring recess and the contact pin 43' will again drop into contactwith the corresponding contact track 31. The dash-dot line Wschematically depicts the path of movement of the contact finger 43 withthe contact pin 43' and the cam member 44 as it moves from one recess 30into the next adjacent recess 30.

Finally, in FIG. 4 there' are shownv details of the circuit board 3 withthe contact tracks 31,32 and the recesses 30. In this arrangement, oneof the 'contact tracks in the form of a contact segment 31 is connectedat the rear side of the circuit board 3 via a conductor 33 with thecontact track 32 shown as asubstantially ring-shaped contact member.Contact tracks 31, recesses 30 and contact fingers 41, 43, as shown inthe arrangement of FIG, 2, could also be arranged such that for eachswitching position of the switch wheel 2, two different contact tracks31 are connected electrically with one another and, not as shown, arespective different contact track 31 with a given ring-shapedcontacttrack 32. The recesses or cutouts 313 and the bores 322 providedat the circuit board 3 serve to receive the sleeve members 13 and shaft220i the switching wheel 2.

It should be apparent from the foregoing detailed description, that theobjects set forth at the outset to the specification have beensuccessfully achieved.

I claim:

1. A multipositional selector-switch comprising a rotatablymounted'switching wheel indexable to assume a number of differentselected switching positions, rotary wiper switch means possessing atleast two contact fingers and carried for rotation by said switchingwheel, a circuit board having a plurality of contact track means, saidcircuit board cooperating with said rotary wiper switch means such thatfor each selected switching position of said switching wheel at leasttwo of said contact track means are electrically coupled with oneanother via said contact fingers, said circuit' board being equippedwith a plurality of spaced recesses, cam means provided for at least oneof said contactfingers, said cam means for each switching position ofsaid switching wheel being located in an associated one of saidrecesses, with said one contact finger thencontacting an associatedcontact track means and the other contact finger contacting anothercontact track means, to thus electrically connect said associatedcontact track means and said another contact track means with oneanother, said cam means upon rotation of said switching ouslyestablished electrical connection of said associated contact track meansand said-another contact track means with one another..

2. A multipositional selector switch as defined inclaim 1, wherein oneof said contact track means is a substantially ringshaped'contactmember, said rotary wiper switch means electrically coupling by means ofsaid contact fingers bearing upon said contact trackmeans saidring-shaped contact member with one of the remaining contact track meansas said switching wheel assumes its different switching positions.

3. A multipositional selector switch as defined in claim 1, wherein thespacing between said contact track means of said circuit board amountsto at least 3 mm. at all locations. 4

4. A multipositional selector switch as defined in claim 1, furtherincluding a switch housing for receiving said switching wheel, rotarywiper switch means and said circuit board, said switch housing beingprovided with through passage openings capable of receiving connectingscrew means for connecting together a plurality of such multipositionalselector switches into a switch assembly. 1

5. A multipositional selector switch as defined in claim 4, wherein saidthrough passage openings for said connecting screw means have associatedtherewith at one side protruding externally conical sleeve means and atthe other side being provided with internal conical surface means, inorder to receive the external conical. protruding sleeve means of theneighboring multipositional selector switch.

6. A multipositionalselector switch comprising a rotatably mountedswitching wheel indexable to assume a number of difi'erent selectedpositions, rotary wiper switch means possessing at least two contactfingers and carried for rotation by said switching wheel, a circuitboard having a plurality of contact track means, said contact trackmeans including a plurality of contact segments and at least onesubstantially ringshaped contact member, said circuit board cooperatingwith said rotary wiper switch means such that for each selectedswitching position of said switching wheel at least two of said contacttrack means are electrically coupled with one another via said contactfingers, said circuit board being equipped with a plurality of spacedrecesses intermediate said contact segments and said ring-shaped contactmember, cam means provided for at least one of said contact fingers,said cam means for each switching position of said switching wheel beinglocated in one. of said recesses, during which time said one contactfinger is in conductive contact with a given associated Contact trackmeans and said other contact finger is in conductive contact with saidring-shaped contact member, to thus electrically connect said associatedcontact track means with said ring-shaped contact member, said cam meansupon rotation of said switching wheel into its next switching positionmoving out of said one recess in a direction away from and substantiallyperpendicular to the surface of said circuit board and then along thesurface of said circuit board, to thereby rapidly raise said one contactfinger provided with said cam means out of said conductive contact withsaid associated contact track means located at said circuit board, tothereby interrupt the previously established electrical connection ofsaid associated contact track means with said ring-shaped contactmember.

7. A multipositional selector switch comprising a rotatably mountedswitching wheel indexable to assume a number of different selectedpositions, rotary wiper switch means possessing at least two contactfingers each having a contact rivet and carried for rotation by saidswitching wheel, a circuit board having a plurality of contact trackmeans, said contact track means including a plurality of contactsegments and at least one substantially ring-shaped contact member saidcircuit board cooperating with said rotary wiper switch means such thatfor each selected switching position of said switching wheel at leasttwo of said contact track means are electrically coupled with oneanother via said contact rivets of said contact fingers, said circuitboard being equipped with a plurality of spaced recesses intermediatesaid contact segments and said ring-shaped contact member, cam meanscarried by at least one of said contact fingers for movement along apath completely out of the operable zone of said plurality of contacttrack means, said cam means therefore never physically contactingplurality of contact track means, said cam.

from the surface of said circuit board and approximately perpendicularthereto and then moving again along the surface of said circuit board,to thereby rapidly raise said one contact fingerprovided with said cammeans out of said conductive contact with said associated contact trackmeans and its associated contact rivet out of physical contact with saidcircuit board, thereby suppressing switch sparking and the spreading ofcontaminants between said plurality of contact track means when movingsaid one contact finger between adjacent ones of said contact trackmeans.

1. A multipositional selector switch comprising a rotatably mountedswitching wheel indexable to assume a number of different selectedswitching positions, rotary wiper switch means possessing at least twocontact fingers and carried for rotation by said switching wheel, acircuit board having a plurality of contact track means, said circuitboard cooperating with said rotary wiper switch means such that for eachselected switching position of said switching wheel at least two of saidcontact track means are electrically coupled with one another via saidcontact fingers, said circuit board being equipped with a plurality ofspaced recesses, cam means provided for at least one of said contactfingers, said cam means for each switching position of said switchingwheel being located in an associated one of said recesses, with said onecontact finger then contacting an associated contact track means and theother contact finger contacting another contact track means, to thuselectrically connect said associated contact track means and saidanother contact track means with one another, said cam means uponrotation of said switching wheel into its next switching position movingout of said associated one recess and along the surface of said circuitboard to thereby rapidly raise said one contact finger provided withsaid cam means from its associated contact track means located at saidcircuit board, to thereby interrupt the previously establishedelectrical connection of said associated contact track means and saidanother contact track means with one another.
 2. A multipositionalselector switch as defined in claim 1, wherein one of said contact trackmeans is a substantially ring-shaped contact member, said rotary wiperswitch means electrically coupling by means of said contact fingersbearing upon said contact track means said ring-shaped contact memberwith one of the remaining contact track means as said switching wheelassumes its different switching positions.
 3. A multipositional selectorswitch as defined in claim 1, wherein the spacing between said contacttrack means of said circuit board amounts to at least 3 mm. at alllocations.
 4. A multipositional selector switch as defined in claim 1,further including a switch housing for receiving said switching wheel,rotary wiper switch means and said circuit board, said switch housingbeing provided with through passage openings capable of receivingconnecting screw means for connecting together a plurality of suchmultipositional selector switches into a switch assembly.
 5. Amultipositional selector switch as defined in claim 4, wherein saidthrough passage openings for said connecting screw means have associatedtherewith at one side protruding externally conical sleeve means and atthe other side being provided with internal conical surface means, inorder to receive the external conical protruding sleeve means of theneighboring multipositional selector switch.
 6. A multipositionalselector switch comprising a rotatably mounted switching wheel indexableto assume a number of different selected positions, rotary wiper switchmeans possessing at least two contact fingers and carried for rotationby said switching wheel, a circuit board having a plurality of contacttrack means, said contact track means including a plurality of contactsegments and at least one substantially ring-shaped contact member, saidcircuit board cooperating with said rotary wiper switch means such thatfor each selected switching positIon of said switching wheel at leasttwo of said contact track means are electrically coupled with oneanother via said contact fingers, said circuit board being equipped witha plurality of spaced recesses intermediate said contact segments andsaid ring-shaped contact member, cam means provided for at least one ofsaid contact fingers, said cam means for each switching position of saidswitching wheel being located in one of said recesses, during which timesaid one contact finger is in conductive contact with a given associatedcontact track means and said other contact finger is in conductivecontact with said ring-shaped contact member, to thus electricallyconnect said associated contact track means with said ring-shapedcontact member, said cam means upon rotation of said switching wheelinto its next switching position moving out of said one recess in adirection away from and substantially perpendicular to the surface ofsaid circuit board and then along the surface of said circuit board, tothereby rapidly raise said one contact finger provided with said cammeans out of said conductive contact with said associated contact trackmeans located at said circuit board, to thereby interrupt the previouslyestablished electrical connection of said associated contact track meanswith said ring-shaped contact member.
 7. A multipositional selectorswitch comprising a rotatably mounted switching wheel indexable toassume a number of different selected positions, rotary wiper switchmeans possessing at least two contact fingers each having a contactrivet and carried for rotation by said switching wheel, a circuit boardhaving a plurality of contact track means, said contact track meansincluding a plurality of contact segments and at least one substantiallyring-shaped contact member said circuit board cooperating with saidrotary wiper switch means such that for each selected switching positionof said switching wheel at least two of said contact track means areelectrically coupled with one another via said contact rivets of saidcontact fingers, said circuit board being equipped with a plurality ofspaced recesses intermediate said contact segments and said ring-shapedcontact member, cam means carried by at least one of said contactfingers for movement along a path completely out of the operable zone ofsaid plurality of contact track means, said cam means therefore neverphysically contacting said plurality of contact track means, said cammeans for each switching position of said switching wheel being locatedin one of said recesses, during which time said one contact finger is inconductive contact via its associated contact rivet with a givenassociated contact track means and the other contact finger being inconductive contact via its associated contact rivet with saidring-shaped contact member, to thereby electrically connect saidassociated contact track means with said ring-shaped contact member,said cam means upon rotation of said switching wheel into its nextswitching position moving out of said one recess in a direction awayfrom the surface of said circuit board and approximately perpendicularthereto and then moving again along the surface of said circuit board,to thereby rapidly raise said one contact finger provided with said cammeans out of said conductive contact with said associated contact trackmeans and its associated contact rivet out of physical contact with saidcircuit board, thereby suppressing switch sparking and the spreading ofcontaminants between said plurality of contact track means when movingsaid one contact finger between adjacent ones of said contact trackmeans.